Scientists have recently been working on discovering more about how diabetes and obesity develop as well as ways to prevent these two diseases. In two studies at the UT Southwestern Medical Center, scientists may be getting closer than ever before to developing new treatment therapies for obesity and diabetes.
In the first study, scientists were looking at figuring out neurons in the brain were responsible for regulating the responses of energy expenditure and blood sugar levels. A number of previous studies found that melanocortin 4 receptors (MC4Rs) that are expressed by neurons controlling the autonomic nervous system regulate glucose metabolism as well as energy expenditure. However, this current study was able to isolate that the expression of receptors by neurons controlling the sympathetic nervous system were actually the key regulators in metabolism. These regulate blood sugar levels and the ability of white fate to become beige fat.
For this study, scientists took a sampling of mice and removed the MC4Rs in neurons controlling the sympathetic nervous system. The results were lower energy levels in the mice and weight gain to the point of obesity, and the development of diabetes. The results showed the MC4Rs is indeed required for the regulation of blood sugar levels, body weight, and energy levels.
In the second study at the UT Southwestern Medical Center, scientists discovered a protein that controls when genes are active that plays an important role in the brain regions that regulate metabolism. They found that a transcription factor – spliced X-box binding protein 1 (Xbp1s) – actually influences how sensitive the body is to insulin and leptin signaling. Insulin and Leptin are hormones that regulate food intake and sugar disposal. When the body begins to resist the actions of insulin and leptin, obesity and diabetes are the resulting outcomes.
According to Dr. Kevin Williams, Assistant Professor of Internal Medicine, this new study looks at the links between the brain and the peripheral endocrine tissues that contribute to regulating body weight and sugar metabolism.
This study also used mice as their test subjects. The scientists found that elevated levels of Xbp1s in mice that were fed a high-fat diet were actually able to fight off the onset of obesity and diabetes. On average, these mice were 30% leaner than mice that were being fed the exact sane diet, but that had normal levels of Xbp1s. The actions of the Xbp1s take place in the pro-opipmelanocortin neurons in the hypothalamic region of the brain. The overall results of the study were that higher results of Xbp1s in the pro-opiomelanocortin neurons resulted in improved body weight, lower blood sugar levels, and a stronger insulin sensitivity in the liver.
Both of these studies are believed to help form new treatment therapies for both obesity and diabetes. By looking are what parts of the body have to malfunction to cause the onset of diabetes and obesity, as well as if different protein levels affect the onset, the researcher may be close to finding these new treatments that they are looking for.